Dehydration system for oil wells



Jan. 23, 1940. R. STEWART DEHYDRATION SYSTEM FOR OIL WELLS 2 Sheets-Sheet 1 Filed Feb. 24, 1938 Bay 5281068'72 Jan. 23, 194%. R. STEWART DEHYDRATION SYSTEM FOR OIL WELLS Filed Feb. 24, -19158 2 Sheets-Sheet 2 M 2 1% 3 Q. l 1 W W m H l 1 lfln m WNW 5, up ....H. 7 S i a W n W \3 Ma Q \w ym W8 Patented Jan. 23, 1940 UNITED STATES PATENT OFFICE DEHYDRATION SYSTEM son on. WELLS Gene Clelland Application February 24, 1938, Serial No. 192,384

4 Claims.

This invention relates to the separation of emulsions of oil, water and gas and particularly to the dehydration of oil in stripper fields where salt water is prevalent and where gas pressure is either very low or entirelyabsent.

The general object of the invention is to provide a system of this character wherein the emulsion is passed through a series of separating chambers wherein the fluids are separated in accordance with their specific gravities and wherein the upflowing gas is scrubbed by contact with bailles to cause the more complete sep-' aration of the gas from the oil, the oil, with what salt water remains therein, being then heat treated to still further separate the water from the oil, the water being siphoned off to a receiving pit and the oil and gas being carried to stock tanks.

Other and more detailed objects will appear more fully hereinafter.

The invention is illustrated in the accompanying drawings wherein:

Fig. 1 is a side elevation of a series of separators connected to the stock tanks, the final separating chamber being broken away.

Fig. 2 is an end elevation of the structure shown in Fig. 1, the final separating tank being broken away to show the heater construction.

Fig. 3 is a fragmentary top plan view of the header and pipes leading from the several oil wells into the header.

Referring to the drawings, In in Figs. 1 and 3 designates a manifold or header into which the oil from one or more wells is carried by the pipes ll, these pipes being provided with an oil lubricator of ordinary and well known construction, which requires no detailed description, there being one of these lubricators l2 for each of the pipe lines II and these lubricators being operated by power from the rod line of the well. Each stroke of the rod line injects a drop of treating compound into the oil lines II, and the treated oil then passes into the manifold II). This manifold serves a two-fold purpose in that it is used as a mixing chamber for the thorough 45 mixing of the treating compound with the emulsion coming from the wells and, secondly, it being on the ground at the lowest level, samples of the oil from each well may be taken without the necessity of climbing to the top of a tank. Valves l3 are provided in the several pipe lines I l.

The emulsion from the chamber I is carried into the base of a vertical separating chamber M. This is made of large diametered pipe and is provided with a series of zig-zag baffles IS. The upper 'end of this chamber I4 is connected to a gas line l6 which has two branches, one of these branches being provided with the pressure relief or pop-ofi valve l1.

Extending upward at a certain inclination is a second separating chamber l8 and the cham- 5 her I4 is connected at about one-third of its height and just below the baflies l5 with the chamber l6 by a pipe l9. This chamber I8. is also in the form of a pipe having approximately the same diameter as the pipe from which the m chamber I4 is formed and is provided with a plurality of bafiies 20. At its lower end, this chamber I8 is provided with a siphon 2| discharging into a pit and at its upper end the chamber !8 is connected by a pipe 22 with the middle portion of a vertical chamber 23, this chamber also being composed of large diametered pipe and having baflles 24 in its upper portion. The upper end of this chamber 23 is connected to the gas pipe I6 and between the chamber I4 and the chamber 23 in this gas line l6, there is disposed the check valve 25. This pipe l6 leads to the top of a separating tank 26. The lower end of the separating chamber 23 is connected by a pipe 21 to a spreader 28 having downwardly 25 extending nozzles or downwardly opening perforations 29, as shown in Fig. 2.

Just above the spreader 28 is a heater 30 formed by a heating chamber which extends transversely through the lower portion of the 30 tank 26 and which communicates at one end with a fire box 3| wherein is disposed a burner 32. This burner or heater 32 may be either arranged to burn distillate or oil or, as illustrated, may be connected by a pipe 33 to the 35 top of the tank 26, so that the gas in the top of the tank may be utilized for this burner. The pipe 33 is, of course, provided with a valve 34. The heating chamber 30 has a flue 35 extending upward from it and extending through the lower 0 portion of the tank 26, then extending laterally out of the tank and then extending upward; in the form of a stack 36 provided with a damper 31 and the hood 38.

Disposed to extend over the heating chamber 45 30 and the horizontal portion of this flue 35 are V-shapecl bafiies 39. These baflles have wire netting 40 disposed on their underfaces and serve to retard the upward flow of the oil or emulsion so that the emulsion may become thoroughly e heated and these ba-flles also act to scrub the water and oil apart. As a consequence, the lower portion of the tank 26 becomesdilled with salt water while the oil rises into the upper portion of the tank and the gas rises into the top of the tank. The upper end of the tank may be provided with a pressure relief valve 4|. Connected to the lower end of the tank 26 is a siphon 42 whereby the salt water collecting in the lower portion of the tank 26 may be carried away to a pit. Extending from the upper portion of the tank is a pipe 43 whereby the oil in the upper portion of the tank is carried oil to the stock tanks 44, two of which are shown, though it is to be understood that any number of stock tanks might be connected up in series. The pipe 43 is connected to the interior of each stock tank by means of the vertical pipe 45 which extends down nearly to the bottom of the corresponding stock tank, each of the vertical pipes 45 being provided with a valve 46. This pips 43 adjacent the tank 26 is provided with the gooseneck 41 to permit the oil in the tank to rise to its level, that is, to permit the oil in the tank to rise above the level of the end of pipe 43 where it enters the tank 26s0 that the oil will hold the gas pressure in the upper end of the tank for lease purposes. By the provision of this gooseneck 41, the gas is prevented from passing along the line 43 but is retained within the upper portion of the tank 26. The tanks 44 are connected at their upper ends by means of pipes 48.

It is to be particularlyunderstood that all chambers and tanks are to be insulated with asbestos or other heat insulating lagging approximately 3" thick. This has not been illustrated because it is common practice to insulate tanks and chambers of this character and forms no part of this invention.

It will be seen that the oil after being mixed with the treating material in the chamber I0 is carried into the vertical chamber 14 and that the gas rising upward in this chamber is scrubbed by the baflles l5 so that the gas is partially separated from the oil and water. From the chamber I4 the liquid in the lower portion of the chamber passes into the inclined chamber IS.

The chamber It! can be used as a mixer if a chemical is used and also provides means for keeping a check on each separate well. In the chamber l4 the gas and the liquid separate and the liquid passes into the chamber l8 in a comparatively quiet manner and gives sufficient time for the free water to separate and drain off.

The specific purpose of the chamber 18 is to separate the free water from the liquid. While, because of the exigencies of space in the accompanying drawings, the chamber l8 has been shown at a relatively slight angle, in actual use the chamber l8 will have an arngle of approximately The liquid as it gradually rises in the chamber I8 is checked by the baflies 20 and this allows the free water to fall back and be drained off by the siphon 2|. In this chamber l8 practically all of the free water is separated, the liquid remaining in the chamber l8 being in the form of an emulsion of oil, gas and water. The

emulsion passes from chamber l8 into chamber 23 and in this chamber practically all of the gas in the emulsion is removed though'there may be still a very small amount of gas in the emulsion as it passes into tank 26. The tank 26 must be large enough to handle the amount of liquid produced by the well or wells, so that the liquid will not pass too quickly through the tank 28 before it is properly heated and treated. The salt water which collects in the lower portion of tank 26 is kept at a temperature high enough to give the desired degree of heat necessary to break up the emulsion. This degree of heat is determined by trial and depends upon the character of the oil being treated, some oils requiring a high degree of heat, almost boiling heat, while others require only a gentle heat. The oil itself is not heated directly but is heated as it rises through the salt water which is kept at a constant level by the siphon 42. The main separation of the water, oil and gas in the emulsion takes place in this tank 26, most of the gas and the free water having been taken care of before the liquid enters tank 26. The gooseneck 41 serves as a seal and allows the oil to rise above the opening of pipe 43, and this allows the oil to pass into the stock tanks 44 without the passage of gas. By providing the gooseneck 41 with the pipe 49, which is open at its upper end, a vacuum is prevented from forming. The pressure in the tank 28 is determined by the pressure relief valve 4| which, of course, can be set to any desired pressure.

. The pipes 45 bring the oil into the stock tanks adjacent the bottom of the stock tanks. This warm oil as it rises to the top keeps the oil in the stock tanks warm and allows whatever impurities may still be in the oil to settle out to the bottom.

In all oil treating systems known to me, either a chemical must be used to break up the emulsion, which is quite expensive, or heat and a chemical must be used. The present system does away to a large extent with the use of chemicals. The length of travel of the oil before it goes into the stock tanks is also an important factor in the treatment of the emulsion and this length of travel my system provides. The chamber l8 separates the free water from the oil at the beginning of the treatment and this is a particularly novel feature. The gas which is separated from the oil in chamber 23 is made available for lease and is not lost. I have provided a very compact and eflicient system of dehydration, which system is in actual use and is operating in a very eflicient manner. The equalizing pipe may or may not be used but by leaving gas in the tanks 44, the gravity of the oil is kept at its highest point.

As stated in the beginning of this specification, this treating system is particularly designed for stripper production where there is generally a great amount of water with a small amount of gas. This apparatus is particularly designed to take care of this large volume of water and to save and store the small amount or gas which is separated therefrom and from the oil.

While I have illustrated certain details of construction and arrangement of parts, I wish it distinctly understood that these might be modified in many ways without departing from the principle of the invention as defined in the appended claims.

What is claimed is:

1. A dehydration system for petroleum emulsions, including in combination a vertically elongated chamber provided with baiiies in its upper portion and into the lower end of which the emulsion flows, an upwardly inclined elongated chamber into the lower part of which the emulsion flows from the first-named chamber, the inclined chamber having means for carrying 01! water from its lower end and having bailles in its upper portion; a second vertically elongated chamber having baiiles in its upper portion and with which the upper end of the inclined chamber communicates; a separating tank with the lower end of which the lower end of the said second chamber communicates; meansfor heating the emulsion within the tank; baflies disposed above the heating means; means for siphoning ofi the water collected in the lower portion of the tank; means for carrying off the oil collected in the tank above the water; and a gas pipe connection between the upper ends of the vertical chambers and the top of the tank.

2. A dehydration system for petroleum emulsions, including in combination a vertically elongated chamber provided with baflies in itsupper portion, means for discharging oil into the lower portion of the vertical chamber beneath the baffles; an upwardly inclined elongated chamber into the lower part of which the emulsion flows from the first-named chamber, the inclined chamber having means at its lower end for carrying oflz water and having ,bailles in its upper portion above the connection of the first chamber therewith; a second vertically elongated chamber having bafiies in its upper portion, the upper end of the inclined chamber communieating with the said second chamber below the battles; a separating tank with the lower end of which the lower end of the second'mentioned vertically elongated chamber communicates; a heating chamber extending into the tank and having a flue extending upward and laterally through the tank; bafiies disposed above the heating chamber and above the flue; means for siphoning oil the water collected in the lower portion of the tank; means for carrying of! the oil collected in the tank above the water; means for carrying off the gas collected in the upper portion of the tank; a gas pipe connection between the upper ends of the vertically elongated chambers and the top of the tank and means for maintaining a predetermined pressure of gas in the upper end of the tank.

3. A dehydration system for petroleum emulsions, including in combination a chemical mixing manifold having means for admitting thereto the oil from a plurality of wells, an elongated vertical chamber into the lower end of which the manifold discharges and having a gas outlet at its upper end, an upwardly inclined separating chamber, means for conducting liquid from the lower portion of the first-named chamber into the lower part of said inclined chamber, the inclined chamber acting as a separator to separate free water from the oil, an elongated vertical chamber having the upper end of the inclined chamber opening thereinto substantially midway of its ends and having a gas outlet at its upper end and a liquid outlet at its lower end, a relatively large separating chamber into which said liquid outlet opens and having heating means in the lower portion of the chamber and having 'baffles' in the lower portion of the chamber whereby to permit the collection of salt water in the lower portion of the chamber above the heating means and a collection of oil in the upper portion of the chamber above the water, a gas pipe leading from the upper portion of the chamber, a stock tank, and means for piping the oil from the upper 'portion'of said last-named chamber into the lower portion of the stock tank.

4. A dehydrating system for petroleum emulsions, including in combination a vertical elongated chamber provided with bafiles in" its'upper portion, means for discharging oil into the lower portion of the chamber below the baffles, an upwardly inclined elongated chamber, means connecting an intermediate portion of the lastnamed chamber with an intermediate portion of the first-namedchamber, the inclined chamber having means at its lower end for carrying 011 water and having baflies in its upper portion above said connecting means, a second vertically elongated chamber having battles in its upper portion and with which the upper end of the inclined chamber communicates just below said baflies, a separating tank, a many-apertured spreader in the lower end of and discharging downwardly into the separating tank and communicating with the lower end of the last-named vertical chamber, a heating chamber extending into the lower end of the separating tank and having a flue extending upward through the tank, a plurality of baflles in the separating tank, means for drawing off the water collected in the lower portion of the separating tank, a stock tank, means for carrying off the oil collected in the separating tank above the water and discharging the oil into the lower portion of the stock tank, and means for carrying off the gas collected in the upper portion of the two firstnamed vertical chambers and the upper end of the separating chamber.

RAY STEWART. 

